Guess Who's Back? is a mixtape by American rapper 50 Cent, released April 26, 2002 on independent label Full Clip Records in the United States. It is his first official release after his 2000 effort Power of the Dollar went unreleased. The album features production by Trackmasters, DJ Clark Kent, Father Shaheed, Sha Money XL, Red Spyda, and Terence Dudley. Guess Who's Back? received generally positive reviews from music critics and peaked at number 28 on the U.S. Billboard 200 chart.
The album's cover image was later used in the video for 50 Cent's song "Piggy Bank". The album was recorded in Canada after 50 Cent was "blacklisted" in the recording industry and was unable to find a studio to work with in the U.S. As of May 2004, the album has sold over 400,000 copies in the United States.
After releasing the album, 50 Cent was discovered by rapper Eminem, who listened to a copy of the album through 50 Cent's attorney, who was working with Eminem's manager, Paul Rosenberg, and he was signed to Interscope Records.